Cast refractory product



Patented Jan. 25, 1927.

UNITED STATES PATENT OFFICE.

-GORDON" S. FULCHER, OF CORNING, NEW YORK, ASSIGNOR TO COIBININGii GLASS WORKS, 0F CORNINIG, NEW YORK, A CORPORATION OF NEW YORK.

CAST REI RACTORY PRODUCT.

1T0 Drawing. Application filed July 27, 1e26, Serial No. 125,327, and in Great Britain Jame 25, 1926.

vIn my application Serial No. 64.1,753, filed May 26, 1923, I disclose a crystalline refractory casting analytically containing silica, alumina, and zirconia, made by fusing a mixture'of raw materials containing alu- .-mina, silica and zirconia, with or without an alkali, and castingthe fused mass into shapes in which it is desired to .use the refractory. v

In my other application Serial No. 47,381, filed July 31, 1925, I have disclosed a process of obtaining a cast annealed refractory article.

I have discovered that the presence of a zirconium compound in a refractory casting exercises beneficial effects on the annealing thereof, in that it lowers the possible annealing range and this apart from the other valuable properties due to the zirconium compound in modifying the characteristics of the unannealed product. The purpose of this application is to cover an annealed cast refractory article containing a zirconium compound. V

In my aforesaid application, Serial No. 61,7 53, I have specifically disclosed. refractories of the following analytical composition I. II. III. V. VI.

SiO: 29. 0 30.0 34. 0 38.0 32. 5 35. 0 A110: 51.0 42. 0 34. 0 35. 5 39. 0 30. 0 ZrO: 18. 0 25. 5 30. 0 13. 5 19. 0 25. 0 NaaO 10. 5 7. 0 7. 5 Ti 01, F610: etc 2. 0 2. 5 2. 0 2. 5 2. 5 2. 5

Annealed castings have also been made with up to 60% zirconia. In general the higher the zirconia, the lowerthe expansion.

I Good results have been obtained with up to 60% zirconia, but for my present pur-' poses the zirconia content should amount U to .at least 10%. The quantity of alkali present should be limited, and should not be'over 15%.

Raw materials of the desiredbatch may, in carrying out myinvention, be melted .in an electric furnace, and when fused, cast into shapes of.desired form for use'as refractories,'the resulting castings being annealed in any appropriate manner, such for instance as burying them in sand. Several methods of annealing are disclosed in my previous application, Serial No.47,381. The

resulting product will consist of crystals embedded in a glassy matrix, the crystals varying in size in accordance with the conditions of manufacture and with the batch used. In certain circumstances thecrystals are microscopic, and the matrix may constitute a substantial proportion of the refractory. The introductionof the zir-j It is usual to give the anal tical compo-' sition of substances such as orin the subject-matter of this a plication'in the percentage of dxides o the various elements resent therein. Hence in certain of the ollowing claims in which the term analtyltically containin is used, I have specified e presence of t e oxides of" certain ele-.

ments without intending tolimit the claims to the presence of such elements in the 0on dltion of free oxides, but merely to indicate in 'quantitieswhich, when determined as oxides, give the percentage called for.'

The word casting in the following claims is used to define an article which has been cast or formed by running molten material into a mold of anydesired form, and

the term refractory casting is used to designate a casting which, when used in. a furnaceof high temperature, will fora prolonger period, successfully withstand the temperatures encountered, and will resist the abrasion and corrosion at the places where used. 1, Having thus described my invention what claim as new, and desire tosecure by Letters Patent is v 1. An annealed refractory casting analytically containing. a compound of zirconium in substantial quantities, and consisting of indigenous crystals in a glassy matrix.

2. Anannealed refractory casting analytically containing zirconia in an amount bethe presence of compounds of such elements tween 10% and 60%, and consisting of in digenous crystals in a glassy matrix.

3. An annealed refractory casting, analytically containing between 10 to 60% zirconia, and silica and alumina. I

4. An annealed refractory casting analytically containin a substantial quantity of zirconia, and a uniina, and Silicafand in which the number of molecules of silica is 10 less than the sum of the number of molecules of zirconia plus two-thirds of the number of mblecules of alumina.

5. An annealed refractory casting analytically cbntaining zirconia between 10% and 60%, and contalning alumina and silica in a ratio greater than 3 t0 2.

In testimony whereof I hereunto aflix my signature.

GORDON s. FULCHER. 

